The second president of the United States John Adams once said: "In politics, the middle way is no way at all".

Mr Adams knew a thing or two about revolutions and knew that, in their midst, you have to pick a side.

With Brexit, we've had our own revolt and it is the middle way which is leading Theresa May inexorably to the most perilous moment of her premiership.

I was initially sceptical that such a threat existed. I still think the most likely outcome is that Mrs May survives and limps on.

But, having talked to several Conservative MPs on both wings of the party today, I believe that there is an increasing possibility she will face a challenge.

Part of the reason for that are Mrs May's own missteps.

She has never - could never recover her authority after the catastrophe of the general election result. Her botched and limited reshuffle adverted to (rather than distracted from) her systemic weakness and resulted in her spending the limited capital she had accrued from December's successful EU negotiations.

Worse, when Brexit is not discussed (as was largely the case in the first half of this week), Tory MPs become restless and darkly whisper that the PM has little in the way of domestic agenda and even less in the way of dynamism. They worry she is shrinking, not growing, into the job. One MP told me: "Both I and the vast majority of Conservative MPs and ministers think she is hopeless."

But her biggest danger comes not from something she has done but instead because of something she has yet to do. With little more than a year to go until B-day and negotiations on the transition and final settlement looming, Mrs May must finally make a series of choices, many of which she has put off for so long.

She must decide what sort of customs arrangement she wants. She must decide how closely Britain will remain aligned to the EU's regulatory regime. She must decide how long she wants the transition to be.

A wrong step in any of these, much less all three, could provoke mutiny. But several Remainer MPs have told me that they are certain no new no-confidence letters have been signed by anyone on their side.

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That's not to say Remainer MPs are content with her. They're despairing. But they cling onto her for fear of getting something worse.

One MP told me: "It would be deeply irresponsible to have a three-month leadership contest at such a critical point in the Brexit negotiations- we run the risk of getting some ghastly Brexiteer like Jacob Rees-Mogg." Given just how Eurosceptic the remaining Tory grassroots are, that isn't an unreasonable assumption.

Naturally, the Brexiteers have no such fear. Rather, they're worried that Mrs May is reneging on the Brexit she promised them. For example, Theresa Villiers in the Sunday Telegraph warns that Britain risks staying in the EU "in all but name".

These developments are crucial. Hitherto the arch-Brexiteers have been May's lifeline. In the wake of the election shambles they made the assessment that, however damaged as she might have been, she remained "the best vehicle for delivering Brexit", as one senior former Brexiteer cabinet minister told me a few weeks ago.

If, through the detail of the negotiations, Mrs May appears likely to deliver a softer Brexit than they would like, that calculus would change and they would strike.

Brexiteers have waited a long time to reach the promised land. If they fear the road there is running out they will not hesitate to try and remove a Prime Minister they don't much care for anyway. As one MP told me, the leadership plots are being orchestrated by "hard Brexiteers who see their mad Brexit vision slipping away".

Mrs May was chosen to be Tory leader because she was offensive to neither side of the Brexit schism. Accordingly she is now about to try and chart a middle course.

But as John Adams could have told her: "This would be the best of all possible worlds, if there were no religion in it". Brexit is not normal politics. It is almost religious. It is a matter of emotion, faith and belief (on both sides).

The problem with religions is that their adherents are prone to visions, something the Prime Minister most certainly is not. Her middle way might seem sensible to outsiders but to Brexit's strongest adherents it will be heretical. And if the rumours are right, it doesn't need many more true believers to trigger the removal of this Pope.

Worse for the Conservatives, there is a possible scenario which would leave them all worse off. Everyone talks as if a vote of no confidence would be the end of Mrs May. As John Adams never said: "It ain't necessarily so".

Forty-eight MPs are needed to trigger a contest but Mrs May does not have to resign. She could fight on. If Remainers and the few loyalists she has band together, she might survive. She would stagger on, but weaker than before. So would everyone else.

It would be Jeremy Corbyn who would emerge all the stronger and, as we know, he has a few revolutionary ideas of his own.